Polyalpha-1,3-glucan esters and articles made therefrom

ABSTRACT

The disclosure generally relates to poly_alpha-1,3-glucan compositions and articles containing them. In particular interest are compositions comprising poly_alpha-1,3-glucan ester derivatives. The poly_alpha-1,3-glucan derivatives are useful in thermoprocesses and in particular, injection molding processes.

This application is the National Stage application of International Application No. PCT/US2017/62508 (filed Nov. 20, 2017), which claims the benefit of U.S. Provisional Application No. 62/425,247 (filed Nov. 22, 2016), both of which prior applications are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The disclosure generally relates to poly alpha-1,3-glucan derivatives for use in thermoprocesses and articles containing the aforementioned, and more particularly, articles made from thermoprocesses and comprising poly alpha-1,3-glucan ester derivatives.

BACKGROUND OF THE INVENTION

Bio-sourced/bio-degradable polymers are in demand as a substitute for incumbent polymeric materials. Poly alpha-1,3-glucan is a polysaccharide derived from enzymatic processes or plant hosts that are biodegradable and can be economically made from renewable resource-based feedstocks. Interest exists in the use of poly alpha-1,3-glucan and/or its derivatives in articles historically comprising incumbent polymers.

SUMMARY OF THE INVENTION

A first aspect of the present invention relates to a composition comprising a poly alpha-1,3-glucan compound represented by the structure:

wherein: (i) n is at least 6 and (ii) each R¹ is independently selected from H or an acyl group, the acyl group being independently selected from the group consisting of: a) an

A second aspect of the present invention relates to a composition comprising: (A) a poly alpha-1,3-glucan compound represented by the structure:

wherein: (i) n is at least 6 and (ii) each R¹ is independently selected from H or an acyl group, the acyl group being independently selected from the group consisting of: (i) an

DETAILED DESCRIPTION OF THE INVENTION Ranges and Preferred Variants

Any range set forth herein expressly includes its endpoints unless explicitly stated otherwise. Setting forth an amount, concentration, or other value or parameter as a range specifically discloses all possible ranges formed from any possible upper range limit and any possible lower range limit, regardless of whether such pairs of upper and lower range limits are expressly disclosed herein. Compounds, processes and articles described herein are not limited to specific values disclosed in defining a range in the description.

The disclosure herein of any variation in terms of materials, chemical entities, methods, steps, values, and/or ranges, etc.—whether identified as preferred or not—of the processes, compounds and articles described herein specifically intends to include any possible combination of materials, methods, steps, values, ranges, etc. For the purpose of providing photographic and sufficient support for the claims, any disclosed combination is a preferred variant of the processes, compounds, and articles described herein.

In this description, if there are nomenclature errors or typographical errors regarding the chemical name any chemical species described herein, including curing agents of formula (I), the chemical structure takes precedence over the chemical name. And, if there are errors in the chemical structures of any chemical species described herein, the chemical structure of the chemical species that one of skill in the art understands the description to intend prevails.

Definitions

As used herein, the article “a” refers to one as well as more than one and does not necessarily limit its referent noun to the grammatical category of singular number.

As used herein, the terms “about” and “at or about”, when used to modify an amount or value, refers to an approximation of an amount or value that is more or less than the precise amount or value recited in the claims or described herein. The precise value of the approximation is determined by what one of skill in the art would recognize as an appropriate approximation to the precise value. As used herein, the term conveys that similar values, not precisely recited in the claims or described herein, can bring about results or effects that are equivalent to those recited in the claims or described herein, for which one of skill in the art would acknowledge as acceptably brought about by the similar values.

The terms “percent by volume”, “volume percent”, “vol %” and “v/v %” are used interchangeably herein. The percent by volume of a solute in a solution can be determined using the formula: [(volume of solute)/(volume of solution)]×100%.

The terms “percent by weight”, “weight percentage (wt %)” and “weight-weight percentage (% w/w)” are used interchangeably herein. Percent by weight refers to the percentage of a material on a mass basis as it is comprised in a composition, mixture or solution.

As used herein, “weight average molecular weight” or “Mw” is calculated as Mw=ΣNiMi²/ΣNiMi; where Mi is the molecular weight of a chain and Ni is the number of chains of that molecular weight. The weight average molecular weight can be determined by techniques such as static light scattering, gas chromatography (GC), high performance liquid chromatography (HPLC), gel permeation chromatography (GPC), small angle neutron scattering, X-ray scattering, and sedimentation velocity.

As used herein, “number average molecular weight” or “Mn” refers to the statistical average molecular weight of all the polymer chains in a sample. The number average molecular weight is calculated as Mn=ΣNiMi/ΣNi where Mi is the molecular weight of a chain and Ni is the number of chains of that molecular weight. The number average molecular weight of a polymer can be determined by techniques such as gel permeation chromatography, viscometry via the (Mark-Houwink equation), and colligative methods such as vapor pressure osmometry, end-group determination, or proton NMR.

The terms “increased”, “enhanced” and “improved” are used interchangeably herein. These terms may refer to, for example, a quantity or activity that is at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 125%, 150%, 175%, or 200% (or any integer between 1% and 200%) more than the quantity or activity for which the increased quantity or activity is being compared.

As used herein, the term “article” refers to an unfinished or finished item, thing, object, or an element or feature of an unfinished or finished item, thing or object. As used herein, when an article is unfinished, the term “article” may refer to any item, thing, object, element, device, etc. that has a form, shape, configuration that may undergo further processing in order to become a finished article. As used herein, when an article is finished, the term “article” refers to an item, thing, object, element, device, etc. that is in a form, shape, configuration that is suitable for a particular use/purpose without further processing of the entire entity or a portion of it.

An article may comprise one or more element(s) or subassembly(ies) that either are partially finished and awaiting further processing or assembly with other elements/subassemblies that together will comprise a finished article. In addition, as used herein, the term “article” may refer to a system or configuration of articles.

The terms “poly alpha-1,3-glucan”, “alpha-1,3-glucan polymer” and “glucan polymer” are used interchangeably herein. Poly alpha-1,3-glucan is a polymer comprising glucose monomeric units linked together by glycosidic linkages, wherein at least about 50% of the glycosidic linkages are alpha-1,3-glycosidic linkages. Poly alpha-1,3-glucan is a type of polysaccharide. The structure of poly alpha-1,3-glucan can be illustrated as follows:

The poly alpha-1,3-glucan that can be used for preparing poly alpha-1,3-glucan ester compounds described herein can be prepared using chemical methods. Alternatively, it can be prepared by extracting it from various organisms, such as fungi, that produce poly alpha-1,3-glucan. Alternatively still, poly alpha-1,3-glucan can be enzymatically produced from sucrose using one or more glucosyltransferase (gtf) enzymes (e.g., gtfJ), such as described in U.S. Pat. Nos. 7,000,000, 9,080,195, and 8,642,757 (all three of which are incorporated herein by reference), for example.

The terms “glucosyltransferase enzyme”, “gtf enzyme”, “gtf enzyme catalyst”, “gtf”, and “glucansucrase” are used interchangeably herein. The activity of a gtf enzyme herein catalyzes the reaction of sucrose substrate to make products poly alpha-1,3-glucan and fructose. Other products (byproducts) of a gtf reaction can include glucose (where glucose is hydrolyzed from the glucosyl-gtf enzyme intermediate complex), various soluble oligosaccharides (DP2-DP7), and leucrose (where glucose of the glucosyl-gtf enzyme intermediate complex is linked to fructose). Leucrose is a disaccharide composed of glucose and fructose linked by an alpha-1,5 linkage. Wild type forms of glucosyltransferase enzymes generally contain (in the N-terminal to C-terminal direction) a signal peptide, a variable domain, a catalytic domain, and a glucan-binding domain. A gtf herein is classified under the glycoside hydrolase family 70 (GH70) according to the CAZy (Carbohydrate-Active EnZymes) database (Cantarel et al., Nucleic Acids Res. 37:D233-238, 2009).

The percentage of glycosidic linkages between the glucose monomer units of poly alpha-1,3-glucan used to prepare poly alpha-1,3-glucan ester compounds described herein that are alpha-1,3 is at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% (or any integer value between 50% and 100%). In such embodiments, accordingly, poly alpha-1,3-glucan has less than about 50%, 40%, 30%, 20%, 10%, 5%, 4%, 3%, 2%, 1%, or 0% (or any integer value between 0% and 50%) of glycosidic linkages that are not alpha-1,3.

Poly alpha-1,3-glucan used to produce poly alpha-1,3-glucan ester compounds described herein is preferably linear/unbranched. In certain embodiments, poly alpha-1,3-glucan has no branch points or less than about 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% branch points as a percent of the glycosidic linkages in the polymer. Examples of branch points include alpha-1,6 branch points, such as those present in mutan polymer.

The terms “glycosidic linkage” and “glycosidic bond” are used interchangeably herein and refer to the type of covalent bond that joins a carbohydrate (sugar) molecule to another group such as another carbohydrate. The term “alpha-1,3-glycosidic linkage” as used herein refers to the type of covalent bond that joins alpha-D-glucose molecules to each other through carbons 1 and 3 on adjacent alpha-D-glucose rings. This linkage is illustrated in the poly alpha-1,3-glucan structure provided above. Herein, “alpha-D-glucose” is referred to as “glucose”.

The terms “poly alpha-1,3-glucan ester compound”, “poly alpha-1,3-glucan ester”, and “poly alpha-1,3-glucan ester derivative” are used interchangeably herein. A poly alpha-1,3-glucan ester compound herein can be represented by the structure:

Regarding the formula of this structure, n can be at least 6, and each R¹ can independently be a hydrogen atom (H) or an acyl group. A poly alpha-1,3-glucan ester compound herein has a degree of substitution of about 0.001 to about 3.0.

Poly alpha-1,3-glucan ester compounds disclosed herein are synthetic, man-made compounds.

A poly alpha-1,3-glucan ester compound is termed an “ester” herein by virtue of comprising the substructure —C_(G)—O—CO—C—, where “—C_(G)—” represents carbon 2, 4, or 6 of a glucose monomeric unit of a poly alpha-1,3-glucan ester compound, and where “—CO—C—” is comprised in the acyl group.

Examples of linear “acyl group” groups herein include:

a methanoyl group (—CO—H), a ethanoyl group (—CO—CH₃), a propanoyl group (—CO—CH₂—CH₃), a butanoyl group (—CO—CH₂—CH₂—CH₃), a pentanoyl group (—CO—CH₂—CH₂—CH₂—CH₃), a hexanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₃), a heptanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), an octanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a nonanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a decanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a undecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a dodecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a tridecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a tetradecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a pentadecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a hexadecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a heptadecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), an octadecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a nonadecanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), an eicosanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), an uneicosanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a docosanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a tricosanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a tetracosanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), a pentacosanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), and a hexacosanoyl group (—CO—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₂—CH₃), for example.

Common names for the above are formyl (methanoyl group), acetyl (ethanoyl group), propionyl (propanoyl group), butyryl (butanoyl group), valeryl (pentanoyl group), caproyl (hexanoyl group); enanthyl (heptanoyl group), caprylyl (octanoyl group), pelargonyl (nonanoyl group), capryl (decanoyl group), lauroyl (dodecanoyl group), myristyl (tetradecanoyl group), palmityl (hexadecanoyl group), stearyl (octadecanoyl group), arachidyl (eicosanoyl group), behenyl (docosanoyl group), lignoceryl (tetracosanoyl group), and cerotyl (hexacosanoyl group). The common names will be used herein when possible.

Examples of branched acyl groups include a 2-methylpropanoyl group; a 2-methylbutanoyl group; a 2,2-dimethylpropanoyl group; a 3-methylbutanoyl group; a 2-methylpentanoyl group; a 3-methylpentanoyl group; a 4-methylpentanoyl group; a 2,2-dimethylbutanoyl group; a 2,3-dimethylbutanoyl group; a 3,3-dimethylbutanoyl group; a 2-ethylbutanoyl group; and a 2-ethylhexanoyl group.

Examples of cyclic acyl groups include a cyclopropanoyl group; a cyclobutanoyl group; a cyclopentanoyl group; a cyclohexanoyl group; and a cycloheptanoyl group.

The carbonyl group (—CO—) of the acyl group is ester-linked to carbon 2, 4, or 6 of a glucose monomeric unit of a poly alpha-1,3-glucan ester compound.

Regarding nomenclature, a poly alpha-1,3-glucan ester compound can be referenced herein by referring to the organic acid(s) corresponding with the acyl group(s) in the compound. For example, an ester compound comprising acetyl groups can be referred to as a poly alpha-1,3-glucan acetate, an ester compound comprising propionyl groups can be referred to as a poly alpha-1,3-glucan propionate, and an ester compound comprising butyryl groups can be referred to as a poly alpha-1,3-glucan butyrate. However, this nomenclature is not meant to refer to the poly alpha-1,3-glucan ester compounds herein as acids per se.

“Poly alpha-1,3-glucan triacetate” herein refers to a poly alpha-1,3-glucan ester compound with a degree of substitution by acetyl groups of 2.75 or higher.

The terms “poly alpha-1,3-glucan monoester” and “monoester” are used interchangeably herein. A poly alpha-1,3-glucan monoester contains only one type of acyl group. Examples of such monoesters are poly alpha-1,3-glucan acetate (comprises acetyl groups), poly alpha-1,3-glucan propionate (comprises propionyl groups), and etc.

The terms “poly alpha-1,3-glucan mixed ester” and “mixed ester” are used interchangeably herein. A poly alpha-1,3-glucan mixed ester contains two or more types of an acyl group. Examples of such mixed esters are poly alpha-1,3-glucan acetate propionate (comprises acetyl and propionyl groups), poly alpha-1,3-glucan acetate butyrate (comprises acetyl and butyryl groups), and etc.

The term “degree of substitution” (DoS or DS) as used herein refers to the average number of hydroxyl groups substituted in each monomeric unit (glucose) of a poly alpha-1,3-glucan ester compound. Each monomeric unit has three hydroxyl groups which can be substituted with acyl groups to form an ester group. Thus, the maximum degree of substitution is 3 for each monomeric unit.

The terms “reaction”, “reaction composition”, and “esterification reaction” are used interchangeably herein and refer to a reaction comprising poly alpha-1,3-glucan, at least one acid catalyst, at least one acid anhydride and at least one organic acid. The reaction is substantially anhydrous. A reaction is placed under suitable conditions (e.g., time, temperature) for esterification of one or more hydroxyl groups of the glucose units of poly alpha-1,3-glucan with an acyl group from at least the acid anhydride or acid chloride, thereby yielding a poly alpha-1,3-glucan ester compound.

Herein, a poly alpha-1,3-glucan that is “acid-exchanged” has been treated with acid to remove water from the poly alpha-1,3-glucan. An acid-exchange process for producing acid-exchanged poly alpha-1,3-glucan can comprise one or more treatments in which the glucan is placed in an acid (e.g., organic acid) and then removed from the acid.

The term “acid catalyst” as used herein refers to any acid that accelerates progress of an esterification reaction. Examples of acid catalysts are inorganic acids such as sulfuric acid (H₂SO₄) and perchloric acid (HClO₄).

The term “acid anhydride” as used herein refers to an organic compound that has two acyl groups bound to the same oxygen atom. Typically, an acid anhydride herein has the formula (R—CO)₂O , where R is a saturated linear carbon chain (up to seven carbon atoms). Examples of acid anhydrides are acetic anhydride [(CH₃—CO)₂O ], propionic anhydride [(CH₃—CH₂—CO)₂O ] and butyric anhydride [(CH₃—CH₂—CH₂—CO)₂O].

The terms “organic acid” and “carboxylic acid” are used interchangeably herein. An organic acid has the formula R—COOH, where R is an organic group and COOH is a carboxylic group. The R group herein is typically a saturated linear carbon chain (up to seven carbon atoms). Examples of organic acids are acetic acid (CH₃—COOH), propionic acid (CH₃—CH₂—COOH) and butyric acid (CH₃—CH₂—CH₂—COOH).

The “molecular weight” of poly alpha-1,3-glucan and poly alpha-1,3-glucan ester compounds herein can be represented as number-average molecular weight (M_(n)) or as weight-average molecular weight (M_(w)). Alternatively, molecular weight can be represented as Daltons, grams/mole, DPw (weight average degree of polymerization), or DPn (number average degree of polymerization). Various means are known in the art for calculating these molecular weight measurements, such as high-performance liquid chromatography (HPLC), size exclusion chromatography (SEC), or gel permeation chromatography (GPC).

Generally

Bio-sourced/bio-degradable polymers are in demand as a substitute for incumbent polymeric materials. Poly alpha-1,3-glucan is a polysaccharide derived from enzymatic processes or plant hosts that are biodegradable and can be economically made from renewable resource-based feedstocks. Poly alpha-1,3-glucan is a highly hydrogen bonded polymer that degrades before it melts, which prevents thermoprocessing, and in particular melt-processing, the polymer into articles. Melt-processing allows for the manufacturing of molded parts, fibers, films, and etc. without the use of solvents.

Cellulose, starch, and related polysaccharides can be made melt-processable by derivatizing them with ester functionalities. Melt-processable starch derivatives have poor mechanical properties due to the amylopectin content. Creating melt-processable cellulose derivatives requires significant up-stream processing to purify the cellulose and decrease the molecular weight to an extent such that the modification reactions can be performed.

Commercially, cellulose thermoplastics are prepared using acetic anhydride, propionic anhydride, butyric anhydride, and combinations thereof [acetic acid (or anhydride)] with propionic anhydride and acetic acid (or anhydride) with butyric anhydride to produce cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. The reactivity of anhydrides decreases with increasing chain length and the cost of anhydrides increases as a function of chain length. The result is substitution with long chain esters (>4 carbon chains) is typically performed through alternative routes which are not commercially practical for cellulose.

Short-chain (<C4) cellulose esters typically need to be plasticized to lower the melt-viscosity to an extent that the materials can be melt-processed. While plasticizers can be used to tune the physical properties, e.g., increase elongation at break and impact strength at the expense of tensile strength and heat deflection temperature, issues such as leaching can have a profound effect on the polymer's performance over time. Many plasticizers, e.g., phthalates, have health concerns. Furthermore, cellulose and starch based-polymers are often plagued with water uptake and dimensional stability. These concerns have lead industry to look for polymers that don't require plasticizers.

A need exists for melt-processable poly alpha-1,3-glucan derivatives that can replace incumbent polymers used in melt-processing manufacturing and articles made therefrom. A need also exists for melt-processable poly alpha-1,3-glucan derivatives that overcome the performance deficiencies mentioned herein.

Applicants have discovered that poly alpha-1,3-glucan derivatives, and in particular, poly alpha-1,3-glucan ester derivatives, address the industry needs described herein.

Embodiments of poly alpha-1,3-glucan ester derivatives and articles made therefrom are disclosed herein.

Applicants have discovered poly alpha-1,3-glucan long-chain, ester derivative compositions and poly alpha-1,3-glucan short-chain ester derivatives plus plasticizer compositions useful in melt-processes to make articles therefrom. The discovery includes the optimization of the ester functionalities, melt and flow characteristics, and plasticizer use which results in articles made therefrom having increased mechanical performance characteristics. Such articles are also transparent if no additional additives are present in the articles which could affect this transparency. Applicants' discoveries are disclosed herein.

Poly alpha-1,3-Glucan Ester Derivatives: Long-Chain Esters

Poly alpha-1,3-glucan ester derivatives useful in thermoprocesses such as melt-processes are disclosed herein. Also disclosed herein are poly alpha-1,3-glucan ester derivatives useful in injection molded parts.

Examples of poly alpha-1,3-glucan ester compounds/compositions include but are not limited to the structure below:

Regarding the formula of structure above, n may be at least 6, and each R¹ can independently be a H or an acyl group. Additionally, the poly alpha-1,3-glucan ester compound has a degree of substitution of about 0.001 to about 3.0.

The acyl group may be independently selected from the group consisting of acetyl;

In an embodiment, a may be independently 7-16. In another embodiment, a may be independently 9-16.

In an embodiment, the acyl group may be a branched ester. Branching/substitution include, but are not limited to alkyls and cyclic groups. In an embodiment, alkyl groups may include t-butyl, neo-pentyl, methyl, ethyl, and etc. In another embodiment, cyclic groups may include non-aromatic and aromatic groups such a phenyl, cyclohexane, and etc.

Poly alpha-1,3-glucan ester compounds as disclosed herein may contain one type of acyl group disclosed herein. For example, one or more R¹ groups ester-linked to the glucose group in the formula below

may be an enanthyl group; the R¹ groups in this particular example would thus independently be hydrogen and enanthyl groups. As another example, one or more R¹ groups ester-linked to the glucose group in the above formula may be a myristyl group; the R¹ groups in this particular example would thus independently be hydrogen and myristyl groups. As another example, one or more R¹ groups ester-linked to the glucose group in the above formula may be a lauroyl group; the R¹ groups in this particular example would thus independently be hydrogen and lauroyl groups. As another example, one or more R¹ groups ester-linked to the glucose group in the above formula may be a benzoyl group; the R¹ groups in this particular example would thus independently be hydrogen and benzoyl groups.

Alternatively, poly alpha-1,3-glucan ester compounds disclosed herein may contain two or more different types of acyl groups. Examples of such compounds contain two different acyl groups, such as (i) acetyl and lauryl groups (poly alpha-1,3-glucan acetate laurate, where R¹ groups are independently H, acetyl, or lauroyl), (ii) acetyl and palmitoyl groups (poly alpha-1,3-glucan acetate palmitate, where R¹ groups are independently H, acetyl, or palmitoyl).

Other embodiments of the two or more different types of acyl groups include those independently selected from the group consisting of acetyl, benzoyl, enanthyl, caprylyl, pelargonyl, capryl, undecanoyl, lauroyl, tridecanoyl, myristyl, pentadecanoyl, palmitoyl, heptadecanoyl stearyl, nonadecanoyl, arachidyl, uneicosanoyl, behenyl, trieicosanoyl, lignoceryl, pentaleicosanoyl, and cerotyl.

Poly alpha-1,3-Glucan Ester Derivatives: Short-Chain Esters Plus Plasticizer

Examples of other poly alpha-1,3-glucan ester compositions include a poly alpha-1,3-glucan ester compound of the structure below and a plasticizer.

Examples of other poly alpha-1,3-glucan ester compounds include but are not limited to the structure below:

Regarding the formula of structure above, n may be at least 6, and each R¹ can independently be a H or an acyl group. Additionally, the poly alpha-1,3-glucan ester compound has a degree of substitution of about 0.3 to about 3.0.

In an embodiment, the acyl group may be a branched ester. Branching/substitution include, but are limited to alkyls and cyclic groups. In an embodiment, alkyl groups may include t-butyl, neo-pentyl, methyl, ethyl, and etc. In another embodiment, cyclic groups may include non-aromatic and aromatic groups such a phenyl, cyclohexane, and etc.

Poly alpha-1,3-glucan ester compounds as disclosed herein may contain one type of acyl group disclosed herein. For example, one or more R¹ groups ester-linked to the glucose group in the formula below

may be an acetyl group; the R¹ groups in this particular example would thus independently be hydrogen and acetyl groups. As another example, one or more R¹ groups ester-linked to the glucose group in the above formula may be a propionyl group; the R¹ groups in this particular example would thus independently be hydrogen and propionyl groups. As another example, one or more R¹ groups ester-linked to the glucose group in the above formula may be a butyryl group; the R¹ groups in this particular example would thus independently be hydrogen and butyryl groups.

Alternatively, poly alpha-1,3-glucan ester compounds disclosed herein may contain two or more different types of acyl groups. Examples of such compounds contain two different acyl groups, such as (i) acetyl and propionyl groups (poly alpha-1,3-glucan acetate proprionate, where R¹ groups are independently H, acetyl, or propionyl), (ii) formyl and propionyl groups (poly alpha-1,3-glucan formate propionate, where R¹ groups are independently H, acetyl, or propionyl).

Other embodiments of the two or more different types of acyl groups include those independently selected from the group consisting of acetyl, propionyl, butyryl, valeryl, caproyl, enanthyl, and caprylyl.

Plasticizers that may be used with the poly alpha-1,3-glucan ester compounds disclosed herein are selected from the group consisting of phthalate esters, phosphate esters, glycerol esters, triethylene glycol based esters, and esters of adipic acid, azelaic acid, citric acid, sebacic acid, and tartaric acid. Embodiments of plasticizers include but are not limited to triethyl citrate, diethyl phthalate, and bis(2-ethylhexyl) adipate.

The compositions disclosed herein may contain poly alpha-1,3-glucan ester compounds disclosed herein in a range from about 50 wt % to about 99 wt % and a plasticizer in a range from about 1 wt % to about 50 wt %. In particular embodiments, the ranges of poly alpha-1,3-glucan ester compounds and plasticizer respectively may be 80 wt % and 20 wt %; 90 wt % and 10 wt %; 95 wt % and 5 wt %; 98 wt % and 2 wt %; and 99 wt % and 1 wt %.

The poly alpha-1,3-glucan ester compounds disclosed herein have a degree of substitution (DoS) of about 0.001 to 3.0, preferably from about 0.3 to 3.0. The range encompasses poly alpha-1,3-glucan mono-ester compounds as well as mixed-ester compounds. Alternatively, the DoS of a poly alpha-1,3-glucan ester compound disclosed herein can be about 1.5 to about 3. In another alternative, the DoS maybe in a range from about 2.2 to about 2.9. Alternatively still, the DoS can be at least about 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, or 3.0. Such poly alpha-1,3-glucan esters can be a monoester or a mixed ester. It would be understood by those skilled in the art that since a poly alpha-1,3-glucan ester compound disclosed herein has a degree of substitution between about 0.3 to about 3.0, the R¹ groups of the compound cannot only be hydrogen.

The percentage of glycosidic linkages between the glucose monomer units of the poly alpha-1,3-glucan ester compound that are alpha-1,3 is at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, or 100% (or any integer between 50% and 100%). In such embodiments, accordingly, the compound has less than about 50%, 40%, 30%, 20%, 10%, 5%, 4%, 3%, 2%, 1%, or 0% (or any integer value between 0% and 50%) of glycosidic linkages that are not alpha-1,3.

The backbone of a poly alpha-1,3-glucan ester compound disclosed herein is preferably linear/unbranched. In certain embodiments, the compound has no branch points or less than about 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% branch points as a percent of the glycosidic linkages in the polymer. Examples of branch points include alpha-1,6 branch points.

The formula of a poly alpha-1,3-glucan ester compound in certain embodiments can have an n value of at least 6. Alternatively, n can have a value of at least 10, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, or 4000 (or any integer between 10 and 4000).

The molecular weight of a poly alpha-1,3-glucan ester compound disclosed herein can be measured as number-average molecular weight (M_(n)) or as weight-average molecular weight (M_(w)). Alternatively, molecular weight can be measured in Daltons or grams/mole. It may also be useful to refer to the DP_(w) (weight average degree of polymerization) or DP_(n) (number average degree of polymerization) of the poly alpha-1,3-glucan polymer component of the compound.

The M_(n) or M_(w) of poly alpha-1,3-glucan ester compounds disclosed herein may be at least about 1000. Alternatively, the M_(n) or M_(w) can be at least about 1000 to about 600000. Alternatively still, the M_(n) or M_(w) can be at least about 10000, 25000, 50000, 75000, 100000, 125000, 150000, 175000, 200000, 225000, 250000, 275000, 300000, 325000, 350000, 375000, 400000, 425000, or 500000 (or any integer between 10000 and 500000), for example.

Articles

Poly alpha-1,3-glucan ester compounds, and compositions comprising poly alpha-1,3-glucan ester compounds and plasticizers are useful in thermal processing methods to make articles. Thermal processing includes melt-processing methods such as extrusion, injection molding, and thermoforming.

Articles comprising poly alpha-1,3-glucan ester compounds, and poly alpha-1,3-glucan ester compositions disclosed herein include flexible packaging; rigid packaging; continuous, free-standing films; and articles made by extrusion molding or injection molding.

Films and other articles comprising poly alpha-1,3-glucan ester compounds herein may exhibit desirable transparency properties when measured according to ASTM D1003:13. The poly alpha-1,3-glucan ester compounds exhibit a total luminous transmittance (T_(t)) of at least 60 percent, preferably at least 70 percent, more preferably at least 80 percent, and most preferably at least 85 percent up to a maximum of about 99.5 percent.

Films and other articles comprising poly alpha-1,3-glucan ester compounds herein may also exhibit desirable haze properties when measured according to ASTM D1003:13. The poly alpha-1,3-glucan ester compounds exhibit a percent haze of 30 percent or less, preferably 25 percent or less, and more preferably less than 20 percent but greater than zero.

Examples of flexible packages include but are not limited to blister pack base, a strip pack base, a metal/plastic sheet, a paper/plastic laminate, a pouch, a wrap, and a bag.

Examples of methods to produce flexible packages from the materials listed above include, but are not limited to compression molding, cast film extrusion, and/or blown film extrusion. Embodiments of compression molding processes encompass processes that involve heating a polymer placed between metal plates or a mold to or above its melting temperature, applying pressure for short time periods (ranging from less than a minute to a few minutes), and allowing the polymer to solidify forming an article. If necessary, cycles can be included where pressure is released and applied repeatedly. Embodiments of cast extrusion encompass processes that involve heating a polymer to or above its melting temperature and extruding the polymer out of a flat die to form a film. In such processes, the film is often extruded onto a casting drum (or some similar conveying device) to allow the film article to properly solidify prior to wind-up onto a roller. Embodiments of blown extrusion encompasses processes that involve heating a polymer to or above its melting temperature and extruding the polymer out of a circular, hoop die to form a bubble that can be cooled or heated, if necessary, while suspended until it is nipped onto a roller as a film article.

Examples of rigid packages include but are not limited to bottles, jars, ready meal trays, trays, cosmetic containers, squeezable tubes, and thin wall containers. Application specific examples include, but are not limited to, trays used for meat or produce, and thin walled containers common as a secondary package in electronics and confectionaries.

Methods to produce rigid packaging from the poly alpha-1,3-glucan ester compounds, and poly alpha-1,3-glucan ester compositions disclosed herein (with or without plasticizers) include, but are not limited to, compression molding, thermoforming, and/or injection molding. Embodiments of compression molding processes encompass processes that involve heating a polymer placed between a mold to or above its melting temperature, applying pressure for short time periods (ranging from less than a minute to a few minutes), and allowing the polymer to solidify forming an article in the shape of a mold. Cycles can be included where pressure is released and applied repeatedly, if needed. Embodiments of thermoforming processes encompass processes that involve heating a sheet of polymer until it can be deformed and subsequently forming the sheet into an article in the shape of a mold typically using a change in pressure such as vacuum or pressure increase where it can cool to maintain the desired mold shape. Embodiments of injection molding processes encompass processes that involve heating a polymer to or above its melting temperature and applying a pressure to push the polymer into a mold where it can solidify to form an article in the shape of the mold.

The continuous, free standing, melt-processable films can be made by methods to that include but are not limited to compression molding, cast extrusion, and/or blown extrusion, as described in the flexible packaging section. Non-melt-processable free-standing films can also be prepared through solvent cast methods.

Articles than can be made by injection molding include any article comprising poly alpha-1,3-glucan ester compounds, and poly alpha-1,3-glucan ester compositions disclosed herein. Embodiments of injection molding processes encompass processes that involve heating a polymer to its melting temperature and applying pressure to force the molten polymer into a mold where it cools and solidifies, taking the shape of the mold.

Additional applications of poly alpha-1,3-glucan ester compounds and poly alpha-1,3-glucan ester compositions disclosed herein include, but are not limited to, meltspun filament and staple fibers for textile, apparel and nonwoven applications, meltblown nonwovens for hygiene, technical and medical applications, melt and hotmelt adhesives and sealants.

Continuous fibers, or yarns can be prepared by a so-called melt spinning process, and are said to be “melt spun”. Melt spinning is a process whereby the polymer is melted and extruded through a hole in a so-called spinneret. In typical textile applications, the spinneret is provided with a plurality of holes, often in the range from 1-2000, each about 0.25 mm in diameter, as typical example. Multiple filaments are thereby extruded from a single spinneret. The melt spun filaments thereby produced are collected in a manner consistent with the desired end use. For example, filament intended for use in continuous form, such as in texturing, is typically wound on a yarn, packaged and mounted on a tension-controlled wind-up. Filaments may be otherwise treated in orientation or texturing as practiced in the industry. In addition, staple fibers may be used as blend fibers with other fibers such as cotton, polyester or mixtures. In addition, other fiber formats such as broad continuous fibers may be produced, as used for example in the manufacture of carpet yarns.

Staple fibers can be prepared by melt spinning a suitable composition into filaments, quenching the filaments, drawing the quenched filaments, crimping the drawn filaments, and cutting the filaments into staple fibers having a length of 0.2 to 6 inches (0.5 to 15 cm).

Nonwoven fabric is a fabric-like material made from fibers bonded together by chemical, mechanical, heat or solvent treatment. Nonwoven fabrics are broadly defined as sheet or web structures bonded together by entangling fiber or filaments (and by perforating films) mechanically, thermally or chemically. They are flat or tufted porous sheets that are made directly from separate fibers, molten plastic or plastic film. They are not made by weaving or knitting and do not require converting the fibers to yarn. Typically, a certain percentage of recycled fabrics and oil-based materials are used in nonwoven fabrics. The percentage of recycled fabrics vary based upon the strength of material needed for the specific use. In addition, some nonwoven fabrics can be recycled after use, given the proper treatment and facilities. For this reason, some consider nonwovens a more ecological fabric for certain applications, especially in fields and industries where disposable or single use products are important, such as hospitals, schools, nursing homes and luxury accommodations. Especially for these applications the compositions of this invention may provide renewable, compostable and inherently biodegradable nonwoven structures with an improved environmental footprint.

Nonwoven fabrics are engineered fabrics that may have a limited life, single-use fabric or a very durable fabric. Nonwoven fabrics provide specific functions such as absorbency, liquid repellence, resilience, stretch, softness, strength, flame retardancy, washability, cushioning, thermal insulation, acoustic insulation, filtration, use as a bacterial barrier and sterility. These properties are often combined to create fabrics suited for specific jobs, while achieving a good balance between product use-life and cost. They can mimic the appearance, texture and strength of a woven fabric and can be as bulky as the thickest paddings. In combination with other materials they provide a spectrum of products with diverse properties, and are used alone or as components of apparel, home furnishings, health care, engineering, industrial and consumer goods.

Non-woven materials are used in numerous applications, including: Medical uses such as isolation gowns, surgical gowns, surgical drapes and covers, surgical masks, surgical scrub suits, caps, medical packaging: porosity allows gas sterilization, gloves, shoe covers, bath wipes, wound dressings; Filter uses such as gasoline, oil and air, water, coffee, tea bags, pharmaceutical industry, mineral processing, liquid cartridge and bag filters, vacuum bags, allergen membranes or laminates with nonwoven layers. Hygiene uses of such materials include uses as wipe materials, as backsheet materials for hygiene products such as pads, diapers or cloths. Sanitary products include baby and child hygiene products, female hygiene products, incontinence products, pads, absorbing pads, wiping cloths. Nonwoven materials may be used in geotextile and agricultural applications to manage erosion, weed growth, the application of water and reagents and the overall growth management or soil management, biodegradable structures may provide a special advantage in these applications.

Meltblown nonwovens are produced by extruding melted polymer fibers through a spin net or die consisting of typical multiple dies with 35-50 holes per inch to form long thin fibers which are stretched and cooled by passing hot air over the fibers as they fall from the die. The resultant web is collected into rolls and subsequently converted to finished products. The fibers differ from other extrusions, particularly spun bond, in that they have low intrinsic strength but much smaller size offering key properties. Often melt blown is added to spun bond to form SM (spun-melt) or SMS (spun-melt-spun) webs, which are strong and offer the intrinsic benefits of fine fibers such as fine filtration, low pressure drop as used in face masks or filters and physical benefits such as acoustic insulation as used in dishwashers.

Hot melt adhesive (HMA), also known as hot glue, is a form of thermoplastic adhesive that is commonly supplied in solid cylindrical sticks of various diameters, designed to be melted in an electric hot glue gun. The gun uses a continuous-duty heating element to melt the plastic glue, which the user pushes through the gun either with a mechanical trigger mechanism on the gun, or with direct finger pressure. The glue squeezed out of the heated nozzle is initially hot enough to burn and even blister skin. The glue is tacky when hot, and solidifies in a few seconds to one minute. Hot melt adhesives can also be applied by dipping or spraying.

In industrial use, hot melt adhesives (HMAs) provide several advantages over solvent-based adhesives. Volatile organic compounds are reduced or eliminated, and the drying or curing step is eliminated. Hot melt adhesives have long shelf life and usually can be disposed of without special precautions. Some of the disadvantages involve thermal load of the substrate, limiting use to substrates not sensitive to higher temperatures, and loss of bond strength at higher temperatures, up to complete melting of the adhesive. This can be reduced by using a reactive adhesive that after solidifying undergoes further curing e.g., by moisture (e.g., reactive urethanes and silicones), or is cured by ultraviolet radiation. Some HMAs may not be resistant to chemical attacks and weathering. HMAs do not lose thickness during solidifying; solvent-based adhesives may lose up to 50-70% of layer thickness during drying.

A sealant is a substance used to block the passage of fluids through the surface or joints or openings in materials, a type of mechanical seal. In building construction sealant is sometimes synonymous with caulking and also serve the purposes of blocking dust, sound and heat transmission. Sealants may be weak or strong, flexible or rigid, permanent or temporary. Sealants are not adhesives but some have adhesive qualities and are called adhesive-sealants or structural sealants.

Sealants, despite not having great strength, convey a number of properties. They seal top structures to the substrate, and are particularly effective in waterproofing processes by keeping moisture out (or in) the components in which they are used. They can provide thermal and acoustical insulation, and may serve as fire barriers. They may have electrical properties, as well. Sealants can also be used for simple smoothing or filling. They are often called upon to perform several of these functions at once.

EXAMPLES

The exemplary compounds identified by “E” in the tables below are intended only to further illuminate and not to limit the scope of compounds, processes, and articles described and recited herein. Comparative examples are identified in the tables below by “C”.

Materials

Solvents and reagents were purchased from Sigma-Aldrich Co. Llc, USA.

Dimethylacetamide (DMAc) is anhydrous grade (99.8%).

Acid chlorides and anhydrides are reagent grade.

Test Methods

Two types of test bars were prepared for analysis, an ASTM D638 type V bar, except the width was 0.25″ instead of 0.125″ and an ASTM D790 flex bar. Molded bars were conditioned at 23° C., 50% R.H. for >40 hours before testing. Tensile bars were tested using an Instron 1123 load frame. The reported elastic modulus is non-standard as an extensometer was not used (the nominal strain was instead calculated from cross-head displacement and initial grip separation). Flex bars were notched using a Tinius Olsen model 899 specimen notcher and impact testing was performed using a Ceast® Resil Impactor (type 6967.000).

The temperature at which the glucan esters melted and flowed was estimated using an Olympus BX53 microscope equipped with a Linkam LTS420 temperature controlled stage. Polymer powder (<1 mg) was placed on a microscope slide pre-loaded into the hot stage and a coverslip was added. The hot stage was heated at a rate of 10° C./min. When the polymer appeared to melt, the heating was paused and mechanical pressure was applied using a tweezers to aid in the melt determination. The heating was then re-engaged and the procedure was repeated to estimate the temperature at which the polymer flowed. Unless otherwise noted, the melt/flow determinations were made on neat (un-plasticized) samples.

Mini-Tensile Bar Preparation

Glucan derivatives were extruded using a DSM Xplore™ model 2005 15 cm³ twin-screw micro compounder. Polymer samples were dried after preparation by vacuum oven followed by Schlenk line, and stored in sealable plastic bags. Plasticized samples were prepared by dry mixing the plasticizer with polymer powder immediately before loading into the micro compounder. Un-plasticized samples were typically extruded at 100 RPM for 1 minute while plasticized samples were extruded for 2 minutes. Samples were injection molded using a DSM Xplore™ 10 cm³ injection molding machine.

Abbreviations

A.C. means acid chloride

An. means anhydride

D.T. means decomposition temperature

TEC means triethyl citrate

DEHA means bis(2-ethylhexyl) adipate

Representative Preparation of Poly Alpha-1,3-Glucan

Poly alpha-1,3-glucan described herein can be prepared using a gtfJ enzyme preparation as described in U.S. Pat. No. 7,000,000; U.S. Patent Appl. Publ. No. 2013/0244288, now U.S. Pat. No. 9,080,195; and U.S. Patent Appl. Publ. No. 2013/0244287, now U.S. Pat. No. 8,642,757 (all of which are incorporated herein by reference in their entirety).

Poly alpha-1,3-glucan polymer can be synthesized, and wet cake thereof prepared, following the procedures disclosed in U.S. Appl. Publ. No. 2014/0179913, now U.S. Pat. No. 9,139,718 (see Example 12 therein, for example), both of which are incorporated herein by reference in their entirety.

A nonlimiting example of the preparation of poly alpha-1,3-glucan is as follows: a slurry of poly alpha-1,3-glucan was prepared from an aqueous solution (0.5 L) containing Streptococcus salivarius gtfJ enzyme (100 unit/L), sucrose (100 g/L) obtained from OmniPur Sucrose (EM8550), potassium phosphate buffer (10 mM) obtained from Sigma Aldrich, and FermaSure®, an antimicrobial agent, (100 ppm) obtained from DuPont adjusted to pH 5.5. The resulting enzyme reaction solution was maintained at 20-25° C. for either 24 hours or 4 hours. A slurry was formed since the poly alpha-1,3-glucan synthesized in the reaction was aqueous insoluble. The poly alpha-1,3-glucan solids produced in the reaction were collected using a Buchner funnel fitted with a 325-mesh screen over 40 micrometer filter paper, forming the wet cake which contains about 60-80 wt % of water.

Glucan dry powder was obtained from wet cake that had been isolated as described above, dried, and sieved to the appropriate mesh grade. In the experiments below, this material is referred to as “poly alpha-1,3-glucan powder”. Poly alpha-1,3-glucan powder contained ˜10% water.

Example 1: Poly Alpha-1,3-Glucan Triacetate

Glucan acetate was prepared using several synthetic routes to produce various degrees of substitution.

*Vacuum dried poly alpha-1,3-glucan powder (124.92 g) was added to stirring DMAc (1000 mL) in a 2 liter reaction kettle. The suspension was heated to 100° C. for ˜40 minutes, cooled to 50° C., and a solution of acetyl chloride (200 mL) in DMAc (230 mL) was added. The viscous solution was stirred at 60° C. for 3.5 hours. The reaction was precipitated into water using a Waring blender. The solid was filtered and washed with aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, water/methanol (60/40 v/v), and soaked in methanol overnight. The mixture was filtered and the solid was washed with methanol before drying in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (186 g, 86% yield). The degree of substitution was determined by ¹H NMR in TFA-d/benzene-d6 (DS_(A)=2.5). SEC (in HIP) indicated a Mw of 176 kDa.

**Poly alpha-1,3-glucan powder (56.20 g, 89% solids) was boiled in water (˜200 mL) for 1 hour and filtered. The solid was suspended in acetic acid (200 mL) for ˜3 minutes and filtered. The acetic acid wash was repeated a second time. To a 1 liter round bottom flask was added acetic acid (500 mL), sulfuric acid (0.56 mL), and the activated glucan (with stirring). The suspension was stirred for 2 minutes and acetic anhydride (125 mL) was added drop-wise over 3 minutes. The reaction was heated to 40° C. and stirred for 3 hours. Additional acetic (100 mL) and sulfuric (0.28 mL) acid were added and the reaction was stirred for an additional 2.5 hours. Water (100 mL) was added and the solution was heated to 108° Cover 1.5 hours. The reaction was cooled to 75° C. and precipitated into ice water using a Waring blender. The precipitate was filtered, washed with water, and soaked in NaHCO₃ (5 wt. %) for 65 hours. The mixture was filtered and the solid was washed with water (3×), methanol (3×), and dried under vacuum at 60° C. The product was isolated as a fine white powder (61.15 g, 72% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(A)=2.7). SEC (in HIP) indicated a Mw of 81 kDa.

Table 1 shows some properties of various poly alpha-1,3-glucan acetates having different degrees of substitution. It was found that the fully substituted material (triacetate) would not melt or flow (even when 15 wt % TEC plasticizer was added). When the degree of substitution was below 1.7 the material would melt, but not flow, and when the degree of substitution was below 0.7, the material would not melt or flow; see table below.

TABLE 1 Acetate Melting Flow Example # DoS temp. temp. Route E1A 0.7 >D.T. >D.T. A.C. E1B 1.7 250° C. >D.T. A.C. E1C 2.1 225° C. 240° C. A.C. E1D* 2.5 215° C. 240° C. A.C. E1E** 2.7 225° C. 240° C. An. E1F 3.0 >D.T. >D.T. An.

Glucan acetate was injection molded into mini-tensile bars both with and without plasticizer. Table 2 shows various properties of these molded mini-tensile bars.

TABLE 2 Tensile Elongation Izod impact Acetate Molding Strength at break strength Example # DoS temp. Plasticizer (MPa) (%) (J/m) E1C 2.1 240° C. none  105 ± 4.7 16.4 ± 0.3 E1C 2.1 210° C. 16% TEC 75.6 ± 6.3 18.7 ± 0.9 E1D 2.5 195° C. 16% TEC 74.6 ± 5.8 16.4 ± 1.7 102 ± 38  E1D 2.5 210° C. 10% TEC 99.6 ± 3.0 15.6 ± 1.3 178 ± 105 E1E 2.7 195° C. 16% TEC 73.2 ± 6.4 14.1 ± 2.8

Example 2: Poly Alpha-1,3-Glucan Acetate Proprionate

Glucan acetate/propionate was prepared with varying ratios of acetate to propionate.

*Vacuum dried poly alpha-1,3-glucan powder (37.20 g) was added to stirring DMAc (400 mL) in a 1 liter reaction kettle. The suspension was heated to 100° C. for ˜90 minutes, cooled to 60° C., and a solution of propionyl chloride (60 mL) in DMAc (40 mL) was added. After 10 minutes, acetic anhydride (40 mL) was added and the reaction was stirred at 60° C. for 4 hours. The reaction was precipitated into water using a Waring blender. The precipitate was filtered and the solid was washed with water, aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, and then soaked in water/methanol (50/50 v/v) overnight. The solid was filtered and washed two additional times with water/methanol (50/50 v/v). The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (63 g, 96% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(A)=0.5, DS_(P)=1.8). SEC (in HIP) indicated a Mw of 124 kDa.

**Poly alpha-1,3-glucan powder (39.21 g, 89.5% solids) was boiled in water (150 mL) for 1 hour and filtered. The solid was suspended in propionic acid (75 mL) for ˜3 minutes and filtered. The propionic acid wash was repeated a second time. To a 1 liter reaction kettle was added propionic acid (200 mL), acetic anhydride (130 mL), sulfuric acid (0.380 mL), the activated glucan (76.919 g), and propionic acid (100 mL). The reaction was heated to 40° C., stirred for 2 hours, and deionized water (100 mL) was added. The solution was heated to 94° C. and stirred for 1 hour. The reaction was allowed to cool before precipitation into water using a Waring blender. The precipitate was washed with water, aqueous NaHCO₃ (2.5 wt. %), water, and methanol. The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (mass=58.9 g; 8100 yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(A)=1.6, DS_(P)=1.1). SEC (in HFIP) indicated a Mw of 68 kDa

While increased propionate content decreased the melting temperature, melt-flow was not observed for any of the fully substituted derivatives (including glucan tripropionate) as shown in Table 3.

TABLE 3 Acetate Propionate Melting Flow Example # DoS DoS temp. temp. Route E2A 2.3 0.7 225° C. >D.T. An. E2B 1.2 1.8 200° C. >D.T. An. E2C 0.5 2.5 200° C. >D.T. An. E2D 0.0 3.0 175° C. >D.T. An. E2E 0.3 1.5 185° C. 200° C. A.C. E2F* 0.5 1.8 185° C. 200° C. A.C. E2G 1.0 1.4 215° C. 215° C. A.C. E2H** 1.6 1.1 215° C. 215° C. An.

Glucan acetate propionate was injection molded into mini-tensile bars and the properties were evaluated as shown in Table 4.

TABLE 4 Tensile Elongation Acetate Propionate Molding Strength at break Example # DoS DoS temp. Plasticizer (MPa) (%) E2F 0.5 1.8 210° C. none 81.6 ± 9.1 14.1 ± 3.8 E2F 0.5 1.8 170° C. 16% TEC 40.1 ± 3.8 22.0 ± 3.0 E2G 1.0 1.4 195° C. 10% TEC 77.5 ± 3.3 16.7 ± 1.7 E2H 1.6 1.1 180° C. 10% TEC 60.9 ± 4.2  9.0 ± 0.7

Example 3: Poly Alpha-1,3-Glucan Acetate Butyrate

Glucan acetate butyrate was made with varying ratios of acetate to butyrate.

* Poly alpha-1,3-glucan powder (130 g, 88% solids) was boiled in deionized water (800 mL) for 1 hour and filtered. The solid was stirred in glacial acetic acid (750 mL) for ˜3 minutes and filtered. The glacial acetic acid wash was repeated a second time. To a 4 liter reaction kettle was added dichloromethane (715 mL), butyric anhydride (1105 mL), butyric acid (750 mL), glacial acetic acid (360 mL), and the activated glucan. A chilled solution of butyric anhydride (59 mL) containing 70% aqueous Perchloric acid (1.3 mL) was added to the stirring reaction mixture. The reaction was slowly heated to 50° C. over a period of 4 hours, and then cooled to ˜30° C. The reaction solution was precipitated into methanol/water (70/30 v/v) using a Waring blender. The solid was washed with methanol, aqueous NaHCO₃ (2.5 wt. %) until pH 7, and then soaked in water overnight. The solid was filtered, washed with methanol, and dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (mass=213 g; 89% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(A)=1.4, DS_(B)=1.6). SEC (in HIP) indicated a Mw of 94 kDa.

⁺Vacuum dried poly alpha-1,3-glucan powder (20.67 g) was added to stirring DMAc (200 mL) in a 500 mL round bottom flask. The suspension was heated to 100° C. for ˜45 minutes, cooled to 60° C., and acetic anhydride (25 mL) was added followed by a solution of butyryl chloride (40 mL) in DMAc (50 mL). The viscous solution was diluted with DMAc (100 mL) and stirred for 5 hours at 60° C. The reaction was precipitated into water using a Waring blender. The solid was filtered and washed with aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, water/methanol (50/50 v/v), and then soaked in water/methanol (50/50 v/v) overnight. The solid was filtered, washed with water/methanol (50/50 v/v), and dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (mass=36.81 g; 94% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(A)=0.8, DS_(B)=1.4). SEC (in HIP) indicated a Mw of 302 kDa.

Unlike glucan acetate and glucan acetate propionate, fully substituted glucan acetate butyrate (DoS=3.0) was found to melt/flow if the butyrate content was approximately greater than 1.4 as shown in table 5

TABLE 5 Acetate Butyrate Melting Flow Example # DoS DoS temp. temp. Route E3A 2.1 0.9 200° C. >D.T. An. E3B 1.6 1.4 175° C. 200° C. An. E3C* 1.4 1.6 175° C. 200° C. An. E3D 1.3 1.7 175° C. 200° C. An. E3E⁺ 0.8 1.4 175° C. 200° C. A.C.

Samples of glucan acetate butyrate were injection molded into mini-tensile bars and the properties were evaluated. See table 6.

TABLE 6 Tensile Elongation Izod impact Acetate Butyrate Molding Strength at break strength Example # DoS DoS temp. Plasticizer (MPa) (%) (J/m) E3C 1.4 1.6 200° C. none 61.2 ± 4.7 12.6 ± 1.5 E3D 1.3 1.7 220° C. none 71.4 ± 0.7  9.2 ± 0.5 141 ±21 E3E 0.8 1.4 210° C. none 49.5 ± 1.6 14.0 ± 1.2 E3E 0.8 1.4 190° C. 10% DEHA 35.2 ± 2.1 16.4 ± 3.1

Example 4: Poly Alpha-1,3-Glucan Formate Acetate

*To a 2 liter reaction kettle was added dichloromethane (350 mL), formic acid (350 mL), and poly alpha-1,3-glucan powder (50.39 g, 88% solids) with stirring. The reaction was cooled to 5° C. and acetic anhydride (300 mL) was added dropwise over 15 minutes. A chilled solution of Perchloric acid (0.50 mL) in acetic anhydride (50 mL) was added dropwise over 15 minutes. The reaction bubbled vigorously initially, but subsided with time. The solution was stirred for 5 hours at 22° C. The reaction was precipitated into methanol using a Waring blender. The solid was washed with methanol, aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, and methanol. The solid was dried under ambient conditions followed by a Schlenk line. The product was isolated as a white powder (61.315 g, 92% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(F)=1.0, DS_(A)=1.7). SEC (in HIP) indicated a Mw of 120 kDa.

Glucan formate acetate was prepared at varying ratios of formate to acetate by changing the reaction stoichiometry and/or addition order. With high formate content, the products contained residual hydroxyl content. With high acetate content, the derivatives were fully substituted, and similar to glucan triacetate, would not melt or flow, as shown in table 7.

TABLE 7 Formate Acetate Melting Flow Example # DoS DoS temp. temp. E4A 1.7 0.8 >D.T. >D.T. E4B* 1.0 1.7 225° C. 250° C. E4C 0.1 2.9 >D.T. >D.T.

A sample of glucan formate acetate was injection molded and the tensile properties were evaluated, see table 8.

TABLE 8 Tensile Elongation Formate Acetate Molding Strength at break Example # DoS DoS temp. Plasticizer (MPa) (%) E4B 1.0 1.7 230° C. 20% TEC 42.4 ± 0.3 8.7 ± 1.0

Example 5: Poly Alpha-1,3-Glucan Formate Propionate

Glucan formate propionate was prepared to compare the melt properties to the other formylated esters. At similar degrees of substitution, it was found to melt at a lower temperature than the formate acetate as shown in table 9

TABLE 9 Formate Propionate Melting Flow Example # DoS DoS temp. temp. E5A 1.2 1.8 200° C. 225° C.

Example 6: Poly Alpha-1,3-Glucan Formate Butyrate

*To a 2 liter reaction kettle was added dichloromethane (350 mL), formic acid (350 mL), poly alpha-1,3-glucan powder (57.01 g, 88% solids) with stirring, and butyric anhydride (425 mL). The reaction was cooled to 15° C. and Perchloric acid (0.50 mL) was added. The reaction bubbled vigorously initially, but subsided with time. The solution was stirred for 5 hours at 30° C. and the reaction was precipitated into methanol using a Waring blender. The solid was isolated by filtration and washed with methanol, aqueous NaHCO₃ (2.5 wt. %) until pH 7, and then soaked in water overnight. The suspension was filtered and the solid was washed with water followed by methanol. The solid was dried in a vacuum oven followed by a Schlenk line. A portion of the product required additional purification, which was accomplished by re-precipitation (chloroform into methanol) and the previous washing steps were repeated (2×methanol, aqueous NaHCO₃ (2.5 wt. %), water, methanol). The product was isolated as a fine white powder (78.30 g, 91% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(F)=1.4, DS_(B)=1.2). SEC (in HIP) indicated a Mw of 65 kDa.

Glucan formate butyrate was prepared at several formate to butyrate ratios with melt and flow temperatures shown in table 10.

TABLE 10 Formate Butyrate Melting Flow Example # DoS DoS temp. temp. E6A* 1.4 1.2 175° C. 200° C. E6B 1.1 1.8 175° C. 175° C.

A sample of glucan formate butyrate was injection molded into mini-tensile bars and the properties were evaluated as shown in table 11.

TABLE 11 Tensile Elongation Formate Acetate Molding Strength at break Example # DoS DoS temp. Plasticizer (MPa) (%) E6A 1.4 1.2 200° C. none 61.7 ± 6.3 14.4 ± 2.3

Example 7: Poly Alpha-1,3-Glucan Hexanoate Acetate

*Vacuum dried poly alpha-1,3-glucan powder (31.65 g) was added to stirring DMAc (300 mL) in a 1 liter reaction kettle. The suspension was heated to 100° C. for 30 minutes, cooled to 50° C., and solutions of hexanoyl chloride (27.5 mL) in DMAc (50 mL) and acetyl chloride (40 mL) in DMAc (50 mL) were added. The reaction was stirred for 4 hours at 60° C. and precipitated into water/methanol (50/50 v/v) using a Waring blender. The solid was washed with water, aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, water/methanol (50/50 v/v) (3X), and methanol. The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (51.88 g, 94% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(H)=0.4, DS_(A)=1.8). SEC (in HFIP) indicated a Mw of 209 kDa.

Glucan Hexanoate Acetate was prepared at various hexanoate to acetate ratios. High hexanoate substitution decreased the melt/flow temperature as shown in table 12.

TABLE 12 Hexanoate Acetate Melting Flow Example # DoS DoS temp. temp. E7A 1.8 0.3 125° C. 150° C. E7B* 0.4 1.8 200° C. 215° C. E7C 0.7 1.6 200° C. 215° C.

Glucan hexanoate acetate was molded and the tensile properties are shown below. The degree of substitution of the hexanoate ester had a large impact on the tensile strength of the material (lower hexanoate substitution gave superior properties) as shown in table 13.

TABLE 13 Tensile Elongation Hexanoate Acetate Molding Strength at break Example # DoS DoS temp. Plasticizer (MPa) (%) E7A 1.8 0.3 180° C. none  22 ± 1.5 17.2 ± 1.7 E7B* 0.4 1.8 220° C. none 88.4 ± 0.2 18.8 ± 2.0

Example 8: Poly Alpha-1,3-Glucan Laurate

*Vacuum dried poly alpha-1,3-glucan powder (51.68 g) was added to stirring DMAc (675 mL) in a 2 liter reaction kettle. The suspension was heated to 100° C. for 1 hour, LiCl (29.225 g) and DMAc (75 mL) were added, and the solution was stirred for 2 hours. The solution was cooled to 60° C. and lauroyl chloride (230 mL) in chilled DMAc (250 mL) was added to the reaction followed by pyridine (100 mL, drop-wise). The solution was stirred for 15 hours and cooled. The solvent was decanted and the gel was precipitated into methanol using a Waring blender. The solid was filtered and washed with methanol, water (2×), and methanol (2×), dried in a vacuum oven overnight, and then on a Schlenk line. The solid was dissolved in chloroform and precipitated into methanol using a Waring blender. The solid was filtered and washed with acetone (2×) and dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (175 g, 95% yield). The degree of substitution was determined via ¹H NMR in CDCl₃ (DS_(L)=2.3). SEC (in THF) indicated a Mw of 336 kDa.

**Vacuum dried poly alpha-1,3-glucan powder (70.94 g) was added to stirring DMAc (675 mL) in a 2 liter reaction kettle. The suspension was heated to 100° C. for 45 minutes, cooled to 60° C., and a solution of lauroyl chloride (300 mL) in DMAc (200 mL) was added. The viscous solution was stirred for 2 hours. The solvent was decanted and the gel was precipitated into methanol using a Waring blender. The solid was filtered and washed with aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, and methanol (2×). The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (214 g, 96% yield). The degree of substitution was determined via ¹H NMR in CDCl₃ (DS_(L)=1.9). SEC (in THF) indicated a Mw of 295 kDa.

Glucan laurate with Degrees of Substitution (DoS) from 1.1 to 2.4 were prepared. We found that the DoS has a marked effect on the melt temperature and the material's properties. For example, glucan laurate with a DoS of 1.1 melts at ˜200° C., but never flows; at a DoS of 2.4, the material melts at ˜100° C. and flows at 125° C. Intermediate DS materials had melt and flow temperatures in-between the two samples as shown in table 14.

TABLE 14 Laurate Melting Flow Example # DoS temp. temp. E8A 1.1 200° C. >D.T. E8B 1.3 200° C. 250° C. E8C 1.5 175° C. 200° C. E8D 1.6 175° C. 200° C. E8E** 1.9 175° C. 190° C. E8F* 2.3 125° C. 150° C. E8G 2.4 100° C. 125° C. E8H 2.5 E8I 2.0

Example 9: Poly Alpha-1,3-Glucan Palmitate

Poly alpha-1,3-glucan palmitate (E9A) was prepared using the procedure of Example E8F except palmitoyl chloride was used in place of lauroyl chloride. The degree of substitution was 2.1 as determined via ¹H NMR in CDCl₃. SEC (in THF) indicated a Mw of 358 kDa.

Glucan laurate E8H, E81, and palmitate E9A were melt blown to prepare nonwoven webs using an extruder and spinneret. The extruder screw diameter was 2.54 cm and the spinneret had 740 nozzles split evenly into 4 rows of 220 μm diameter. The spinneret had capillaries with a length-to-diameter ratio of 24:1. A 200 μm stainless-steel wire mesh filter screen was used to prevent non-melting particles from clogging the spinneret. Polypropylene (PP) was used as a comparative example.

Pellets of E8H, E81, and E9A were dried overnight at 105° C. The polypropylene sample used was Moplen HP2774 available from Lyondellbasell. The degree of substitution was quantified by NMR analysis and the average molecular weight was calculated from SEC data. The melt blowing processing parameters used for each ester sample are shown in Table 15.

TABLE 15 Processing Parameters for Melt Blowing Sample PP E8H E8I E9A Extruder Zone 1 (° C.) 170 130 150 140 Extruder Zone 2 (° C.) 200 180 180 180 Extruder Zone 3 (° C.) 215 210 210 210 Clamp Ring Temperature (° C.) 220 215 225 215 Actual Die A Temperature (° C.) 220 215 230 215 Actual Die B Temperature (° C.) 220 215 230 215 Extruder Speed (RPM) 55 55 55 55 Melt Temperature (° C.) 217 213 219 213 Melt Pressure (psi) 670 759-800 790 400-1100 Die Air Temperature Set PT 190 225 240 225 (° C.) Die Air Temperature (° C.) 190 225 240 225 Die Air Pressure (psi) 10 5.0 5.0 5.4 Air Over Temperature Actual 241 404 423 404 (° C.) Ambient Temperature (° C.) 30 24.4 27.8 26.1 Die to Collector Distance (m) 0.45 0.13 0.13 0.20

E8H was difficult to melt blow because it started to melt on the screw, thus preventing continuous feeding of the polymer through the nearby extruding zones. The web produced had very thick and brittle fibers and was not tested further for its performance properties. E81 and E9A were successfully melt blown, as was the polypropylene sample.

The polypropylene produced a white web, whereas E81 and E9A produced a light gold colored web. There was poor cohesion of E81 and E9A fibers resulting in weak webs with easily detachable fibers.

Various properties of the melt blown webs are shown in Table 16. Areal density was measured in accordance with WSP 130.1.R⁴, thickness was measured in accordance with WSP 120.6.R⁴ (12), tensile strength was measured in accordance with NWSP 110.4.R0 (15)—option A, and air permeability was tested in accordance with standard BS EN ISO 9073-15:2008. Fiber diameter was analyzed using scanning electron microscopy (SEM) and Image Pro Plus software was used to measure the fiber diameter from the image. Fiber diameters were taken manually across the width of each fiber. Fiber diameters in the table were the average of 75 measurements.

The mean fiber diameter in the polypropylene webs was lower and had a narrower distribution than the fibers in the E81 and E9A produced webs. The air permeability was much higher for E81 and E9A webs than for polypropylene, likely due to larger pore sizes within the web.

The dry and wet tensile strengths were much lower for the melt blown webs produced from E81 and E9A than for polypropylene.

TABLE 16 Melt Blown Web Properties E8H Sample PP web web E8I web E9A web Average Areal 60.86 ± 1.93 n.d. 55.89 ± 1.23  58.97 ± 2.75  Density (gsm) Average Thick-  0.44 ± 0.03 n.d. 0.33 ± 0.01 0.44 ± 0.04 ness (mm) Air Permeability 16.40 ± 0.43 n.d. 37.62 ± 2.55  65.14 ± 6.06  at 100 Pa (cm³ · cm⁻² · s⁻¹) Fibre Diameter  3.18 ± 1.66 n.d. 6.16 ± 2.96 7.23 ± 3.45 (μm) Dry Tensile 22.72 ± 0.67 n.d. 0.97 ± 0.27 0.64 ± 0.07 Strength (N/25 mm) Wet Tensile  2.67 ± 0.16 n.d. Below Below Strength detection detection (N/25 mm) n.d.—not determined

Wettability of these nonwoven webs was measured using both water and oil and the results are shown in Table 17. A pipette was used to deposit 25 μL of distilled water (72.04 mN.m-1) and generic oil (29.81 mN.m-1) on the surface of the webs. A digital camera was used to capture the wetting of the droplet on melt blown surfaces, and the contact angle was measured using Image Pro software. The polypropylene, E81, and E9A webs were all hydrophobic and oleophillic but E81 and E9A webs were about 10% less hydrophobic than polypropylene.

TABLE 17 Wetting Properties of Melt blown Webs E8H Sample PP web web E8I web E9A web Average 116.40 ± 3.84 n.d. 106.49 ± 1.51 103.85 ± 1.70 Contact Angle w/ Water (°) Average  0 ± 0 n.d.  12.13 ± 0.70  9.35 ± 1.11 Contact Angle w/ Oil (°)

Glucan laurate was injection molded without plasticizer. Compared to the previous derivatives, the long chain ester significantly decreased the tensile strength, but substantially increased the elongation at break as shown in Table 18.

TABLE 18 Tensile Elongation Izod impact Laurate Molding Strength at break strength Example # DoS temp. (MPa) (%) (J/m) E8F 2.3 125° C. 7.6 ± 0.4 39.6 ± 6.9 E8E 1.9 190° C. 8.8 ± 1.2 55.9 ± 18  33 ± 6

Example 10: Poly Alpha-1,3-Glucan Laurate Acetate

Glucan laurate acetate has been prepared at varying amounts of laurate content to assess the physical properties as shown in table 19.

*Vacuum dried poly alpha-1,3-glucan powder (47.07 g) was added to stirring DMAc (450 mL) in a 1 liter reaction kettle. The suspension was heated to 100° C. for 30 minutes, cooled to 60° C., and a solution of lauroyl chloride (130 mL) in DMAc (100 mL) was added. After 5 minutes, acetic anhydride (53 mL) was added dropwise to the reaction, which was stirred at 60° C. for 4.5 hr. The viscous solution was precipitated into methanol using a Waring blender. The solid was filtered and washed with MeOH, aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, and methanol (2×). The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (120.27 g, 92% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(L)=1.4, DS_(A)=0.7). SEC (in THF) indicated a Mw of 215 kDa.

**Vacuum dried poly alpha-1,3-glucan powder (54.25 g) was added to stirring DMAc (550 mL) in a 1 liter reaction kettle. The suspension was heated to 100° C. for 45 minutes, cooled to 50° C., and solutions of lauroyl chloride (35 mL) in DMAc (25 mL) and acetyl chloride (100 mL) in DMAc (50 mL) were added. The reaction was heated to 60° C. and stirred for 3 hours. The viscous solution was precipitated into water/methanol (50/50 v/v) using a Waring blender. The solid was filtered and washed with water, aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, and methanol (3×). The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine off-white powder (87.57 g, 82% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(L)=0.2, DS_(A)=2.5). SEC (in THF) indicated a Mw of 335 kDa.

TABLE 19 Laurate Acetate Melting Flow Example 10 # DoS DoS temp. temp. E10A* 1.4 0.7 175° C. 220° C. E10B 0.7 1.4 220° C. 220° C. E10C 0.5 2.0 200° C. 225° C. E10D** 0.2 2.5 200° C. 225° C.

Glucan laurate acetate was injection molded into mini-tensile bars without plasticizer, and the tensile properties are shown in the table 20. Samples with high laurate content were found to have low tensile and impact strength and high elongation at break, whereas samples with low laurate content showed the opposite trend, see table below.

TABLE 20 Tensile Elongation Izod impact Laurate Acetate Molding Strength at break strength Example # DoS DoS temp. (MPa) (%) (J/m) E10A 1.4 0.7 220° C. 14.6 ± 1.3 74.8 ± 22.6 29 ± 2 E10B 0.7 1.4 225° C. 30.4 ± 1.9 19.4 ± 1.2  24 ± 7 E10C 0.5 2.0 185° C. 39.2 ± 1.5 16.7 ± 1.5  53 ± 8 E10D 0.2 2.5 230° C.   69 ± 10.8 9.2 ± 1.4 218 ± 49

Example 11: Poly Alpha-1,3-Glucan Palmitate Acetate

*Vacuum dried poly alpha-1,3-glucan powder (53.64 g) was added to stirring DMAc (450 mL) in a 1 liter reaction kettle. The suspension was heated to 100° C. for 60 minutes, cooled to 50° C., and solutions of palmitoyl chloride (95 mL) in DMAc (75 mL) and acetyl chloride (75 mL) in DMAc (75 mL) were added. The reaction was heated to 60° C. and stirred for 4 hours. The viscous solution was precipitated into water/methanol (50/50 v/v) using a Waring blender. The solid was filtered and washed with water, aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, and soaked in water/methanol (50/50 v/v) for 16 hours. The solid was filtered and soaked in methanol for 48 hours, re-filtered, and washed twice with methanol. The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (102.6 g, 87% yield). The degree of substitution was determined by ¹H NMR in CDCl₃ (DS_(Pa)=0.4, DS_(A)=2.1). SEC (in THF) indicated a Mw of 294 kDa.

Glucan palmitate acetate was prepared at varying degrees of substitution. The materials melted at a similar temperature, but the polymer with higher palmitate substitution flowed at a lower temperature as shown in table 21.

TABLE 21 Palmitate Acetate Melting Flow Example # DoS DoS temp. temp. E11A 1.54 0.7 175° C. 180° C. E11B* 0.4 2.1 175° C. 215° C.

Glucan palmitate acetate was injection molded into mini-tensile bars and the tensile properties evaluated as shown in table 22.

TABLE 22 Tensile Elongation Palmitate Acetate Molding Strength at break Example # DoS DoS temp. Plasticizer (MPa) (%) E11B 0.4 2.1 210° C. none 49.7 ± 3.4 20.9 ± 1.3

Example 12: Poly Alpha-1,3-Glucan Benzoate Acetate

Poly alpha-1,3-glucan powder (30.60 g) was added to stirring DMAc (275 mL) in a 1 liter reaction kettle. The suspension was heated to 100° C. for 45 minutes, cooled to 60° C., and a solution of benzoyl chloride (43 mL) in DMAc (50 mL) was added. The reaction was stirred for 3 hours at 60° C. at which time acetyl chloride (46 mL) in DMAc (50 mL) was added. The reaction was stirred for an additional 4.5 hours and precipitated from a water/methanol (50/50 v/v) solution using a Waring blender. The resulting solid was washed with water, then aqueous NaHCO₃ (5 wt. %) until pH 7, water, water/methanol (50/50 v/v) (3X), and methanol (3X). The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a fine white powder (51.79 g, 82% yield). The degree of substitution was determined by 1H NMR in CDCl3 (DS(Benzoyl)=0.8, DSA=1.8). SEC (in HFIP) indicated a Mw of 216 kDa. The product was blended with 16 wt. % diethyl phthalate (DEP) plasticizer and injection molded into mini-tensile bars and the properties shown in table 23.

TABLE 23 Tensile Elongation Benzoate Acetate Molding Strength at break Example # DoS DoS temp. Plasticizer (MPa) (%) 12 0.8 1.8 215° C. 16% DEP 36 ± 6.7 6.7 ± 2.1

Example 13: Poly Alpha-1,3-Glucan Acetate Pivalate

Vacuum dried poly alpha-1,3-glucan powder (4.55 g) was added to stirring DMAc (40 mL) in a 250 mL round bottom flask. The suspension was heated to 100° C. for 30 min, cooled to 60° C., and acetic anhydride (5.3 mL) was added to the reaction followed by a solution of pivaloyl chloride (10 mL) in DMAc (15 mL). The reaction was then stirred at 60° C. for 5 hours. The viscous solution was precipitated from a water/methanol (50/50 v/v) solution using a Waring blender. The solid was filtered and washed with water, aqueous NaHCO₃ (2.5 wt. %) until pH 7, water, and water/methanol (50/50 v/v) (3×). The solid was dried in a vacuum oven followed by a Schlenk line. The product was isolated as a white powder (7.43 g, 93% yield). The degree of substitution was determined by 1H NMR in CDCl3 (DSA=1.19, DS(pivalate)=0.78). The melting temperature range of the polymer was 225-235° C. determined using a hot stage microscope.

Film Samples

Film samples were prepared for analysis according to ASTM D882. Film strips with 1 inch width and 6 inch length and tensile bars with a length of 80 mm and an inner width of 0.5 inches were prepared. The test samples were conditioned at 23° C., 50% relative humidity for greater than 40 hrs. Tensile bar samples were tested using an Instron 1122 load frame with a 2000 g load cell. Film strip samples were tested using an Instron 4391 load frame with a 250 lb. load cell that had been modified with longer extension capabilities.

Poly alpha-1,3-glucan Laurate Films

A film sample of poly alpha-1,3-glucan laurate (DoS 2.4) was prepared using 4.0 grams of vacuum-oven dried powder. The powder was placed between Teflon sheets and the Teflon sheets sandwiched between two metal plates. The metal plates were placed between the platens of a PHI, Manual, Bench Design, Hydraulic Compression Press (model #PW220C4-X1) at room temperature. The platens were closed without applying any additional pressure and the sample heated to 150° C. The sample was then subjected to the following compression cycle. First, 10,000 lbs. of pressure were applied for 1 min followed by a release of pressure for 1 min. This process was repeated twice for a total of three cycles. The sample was then exposed to 30,000 lbs. of pressure for 30 sec. followed by cooling to room temperature under pressure by running cooling water through the platens. The sample was removed from the press to provide a transparent film which was flexible enough to be folded without tearing. Table 24 shows some properties of the film.

TABLE 24 Stress @ Strain @ Thickness Width Modulus Max Max (in) (in) (MPa) (MPa) (%) 0.0050 0.50 69.3 ± 12.7 5.9 ± 0.8 106.1 ± 18.4

A film sample of poly alpha-1,3-glucan laurate having a DoS of laurate of 1.7 was prepared using 4.0 grams of vacuum-oven dried powder. The powder was placed between Teflon sheets and the Teflon sheets sandwiched between two metal plates. The metal plates were placed between the platens of a PHI, Manual, Bench Design, Hydraulic Compression Press (model #PW220C4-X1) at room temperature. The platens were closed without applying additional pressure and the sample heated to 200° C. The sample was then subjected to a compression cycle. First, 10,000 lbs. of pressure were applied for 1 min followed by a release of the pressure for 1 min. This process was repeated twice for a total of three cycles. After this, 30,000 lbs. of pressure were applied to the sample for 30 sec. The sample was then cooled to room temperature under pressure by running cooling water through the platens. Once room temperature was reached, the sample was removed from the metal plates and the Teflon sheet to provide a transparent film which was flexible enough to be folded without tearing. Table 25 shows some properties of the film.

TABLE 25 Stress @ Strain @ Thickness Width Modulus Max Max (in) (in) (MPa) (MPa) (%) 0.0030 0.50 175.7 ± 44.5 10.6 ± 0.7 21.4 ± 3.2 Poly alpha-1,3-glucan Diacetate Film

A film sample of poly alpha-1,3-glucan diacetate (DoS of Acetate 2.5) was prepared by mixing 16 wt. % triethyl citrate (obtained from Sigma Aldrich) with poly alpha-1,3-glucan diacetate and extruded using a DSM Xplore™ model 2005 15 cm³ twin-screw micro compounder to form a plasticized material which was ground into small particles and dried in a vacuum-oven overnight. 4.0 grams of the dried material was placed between two Teflon sheets and the Teflon sheets then sandwiched between two metal plates which were placed between the platens of a PHI, Manual, Bench Design, Hydraulic Compression Press (model #PW220C4-X1) at room temperature. The platens were closed without applying additional pressure and the sample was heated to 195° C. The sample was then subjected to a compression cycle. First, 10,000 lbs. of pressure was applied for 1 min followed by a release of the pressure for 1 min. This process was repeated twice for a total of three cycles. The sample was then subjected to 30,000 lbs. of pressure for 30 sec. and then cooled to room temperature while still under pressure by running cooling water through the platens. Once room temperature was reached, the sample was removed from the metal plates and the Teflon sheet to provide a film. Table 26 shows some properties of the film.

TABLE 26 Stress @ Strain @ Thickness Width Modulus Max Max (in) (in) (MPa) (MPa) (%) 0.0087 1.0 1464.9 ± 317.5 11.4 ± 2.4 0.9 ± 0.1 Poly alpha-1,3-glucan Laurate Acetate Film

A film sample of glucan laurate acetate (DoS of Laurate 1.4, DoS of Acetate 0.7) was prepared using 4.0 grams of vacuum-oven dried powder. The dried powder was placed between Teflon sheets and the Teflon sheets sandwiched between two metal plates. The metal plates were placed between the platens of a PHI, Manual, Bench Design, Hydraulic Compression Press (model #PW220C4-X1) at room temperature. The platens were closed without applying additional pressure and the sample heated to 220° C. and subjected to a compression cycle. First, 10,000 lbs. of pressure was applied for 1 min followed by a release of the pressure for 1 min. This process was repeated twice for a total of three cycles. The sample was then subjected to 30,000 lbs. of pressure for 30 sec. The sample was then cooled to room temperature under pressure by running cooling water through the platens. Once room temperature was reached, the sample was removed from the metal plates and the Teflon sheet to provide a transparent film which was flexible enough to be folded without tearing. Table 27 shows some properties of the film.

TABLE 27 Stress @ Strain @ Thickness Width Modulus Max Max (in) (in) (MPa) (MPa) (%) 0.0027 0.50 330.8 ± 104.7 10.6 ± 2.6 21.5 ± 9.0

Film Transparency

Several poly alpha-1,3-glucan esters as disclosed herein were formed into films and tested for transparency (light transmission) and haze values with the results shown in Table 28. Light transmission analysis was measured using a Cary 5000 UV-VIS-NIR spectrophotometer equipped with an integrated sphere. Total luminous transmittance (T_(t)) was measured according to ASTMD1003:13. Haze analysis was completed with the same instrument configuration, per ASTM D1003:13. Film thickness tested ranged from 2 to 3.25 mm.

TABLE 28 Sample DoS Thickness (mm) T_(t) (%) Haze (%) Glucan 2.5 A* 3.25 60 29 acetate Glucan 0.4 L**, 2.3 A 2 76 21 laurate acetate Glucan  1.4 L, 0.8 A 3.25 84 18 laurate acetate Glucan 2.2 L  3.25 83 21 laurate *A is acetate **L is laurate

The results in Table 28 clearly show that poly alpha-1,3-glucan esters as disclosed herein exhibit transmittance of at least 60 percent. Poly alpha-1,3-glucan esters which comprise both acetate and laurate acyl groups, or laurate acyl groups alone, exhibit superior transmittance than poly alpha-1,3-glucan esters which only comprise acetate acyl groups.

Comparative Examples

Cellulose acetate (DS 2.5) (C1) and cellulose acetate butyrate (DS_(A)=1.2, DS_(B)=1.7) (C2) were injection molded into mini-tensile bars and the tensile properties evaluated as shown in table 29.

TABLE 29 Tensile Elongation Impact Strength at Break Strength plasticizer (MPa) (%) (J/m) C1 16% TEC 64 23 46 C2 none 51 21 80

The cellulose diacetate (C1) and cellulose acetate butyrate (C2) compositions tended to be less stiff, have lower tensile strength, have lower impact strength, and have higher elongation at break as compared to the poly alpha-1,3-glucan ester compounds and poly alpha-1,3-glucan ester compositions disclosed herein.

In accordance with the invention disclosed, poly alpha-1,3-glucan ester compounds and poly alpha-1,3-glucan ester compositions, and articles made from the aforementioned have been provided that satisfy the advantages described herein.

Embodiments

For further illustration, additional non-limiting embodiments of the present disclosure are set forth below.

For example, embodiment 1 is a composition comprising a poly alpha-1,3-glucan compound represented by the structure:

wherein: (i) n is at least 6 and (ii) each R¹ is independently selected from H or an acyl group, the acyl group being independently selected from the group consisting of:

a) an acetyl;

b) a benzoyl;

Embodiment 2 is the composition of embodiment 1, wherein the poly alpha-1,3-glucan compound has a Degree of Substitution in a range from about 0.3 to about 3.

Embodiment 3 is the composition of embodiments 1-2, wherein the poly alpha-1,3-glucan compound has a Degree of Substitution in a range from about 1.5 to about 3.

Embodiment 4 is the composition of embodiments 1-3, wherein the poly alpha-1,3-glucan compound has a Degree of Substitution in a range from about 2.2 to about 2.9.

Embodiment 5 is the composition of embodiments 1-4, wherein a is independently 7-16.

Embodiment 6 is the composition of embodiments 1-5, wherein a is independently 9-16.

Embodiment 7 is the composition of embodiments 1-6, wherein R¹ is an acetyl, and

and a is 10.

Embodiment 9 is the composition of embodiments 1-4, wherein R¹ is an acetyl and benzoyl.

Embodiment 11 is the composition of embodiment 1, wherein R¹ is acetyl with a

Embodiment 13 is the composition of embodiment 1, wherein R¹ is acetyl with a Degree of Substitution in a range from about 1.7 to about 1.9; and benzoyl with a Degree of Substitution in a range from about 0.6 to about 0.8.

Substitution in a range from about 0.15 to about 1.8.

Embodiment 15 is the composition of embodiment 1, wherein R¹ is acetyl and

wherein two R³ are methyl groups, and the third R³ is H.

Embodiment 16 is the composition of embodiments 1-2, wherein R¹ is acetyl and benzoyl.

Embodiment 17 is the composition of embodiment 16, wherein the Degree of Substitution of acetyl is in a range from about 1.7 to about 1.9 and the Degree of Substitution of benzoyl is in a range from about 0.6 to about 0.8.

Embodiment 18 is the composition of embodiment 1, wherein R¹ is at least one

wherein one R³ is H, another R³ is ethyl, and the third R³ is a linear butyl group.

Embodiment 19 is the composition of embodiment 1, wherein R¹ is at least one

wherein a is 15.

Embodiment 20 is the composition of embodiment 1, wherein R¹ is at least one

For example, embodiment 21 is a composition comprising:

(A) a poly alpha-1,3-glucan compound represented by the structure:

wherein: (i) n is at least 6 and (ii) each R¹ is independently selected from H or an acyl group, the acyl group being independently selected from the group consisting of:

-   -   (i) an acetyl,     -   (ii) formyl

(B) a plasticizer.

Embodiment 22 is the composition of embodiment 21, wherein the poly alpha-1,3-glucan compound has a Degree of Substitution in a range from about 1.5 to about 3.

Embodiment 23 is the composition of embodiments 21-22, wherein poly alpha-1,3-glucan compound has a Degree of Substitution in a range from about 2.4 to about 3.

Embodiment 25 is the composition of embodiment 21, wherein R¹ is acetyl with a Degree of Substitution in a range from about 0.2 to about 1.6; and

wherein a is 1 with a Degree of Substitution in a range from about 1.1 to about 2.5.

Embodiment 28 is the composition of embodiment 21, wherein R¹ is an acetyl.

Embodiment 29 is the composition of embodiment 28, wherein R¹ has a Degree of Substitution in a range from about 2.1 to about 2.7.

Embodiment 30 is the composition of embodiment 21, wherein R¹ is an acetyl and formyl.

Embodiment 31 is the composition of embodiment 30, wherein R¹ is acetyl with a Degree of Substitution in a range from about 0.8 to about 2.9 and formyl with a Degree of Substitution in a range from about 0.1 to about 1.7.

Embodiment 34 is the composition of embodiments 21-22, wherein R¹ is formyl; and

and and a is 2.

Embodiment 36 is the composition of embodiments 21-34, wherein the plasticizer is selected from the group consisting of phthalate esters, phosphate esters, glycerol esters, triethylene glycol based esters, and esters of adipic acid, azelaic acid, citric acid, sebacic acid, and tartaric acid.

Embodiment 37 is the composition of embodiments 21-36, wherein the plasticizer is selected from the group consisting of triethyl citrate, diethyl phthalate, and bis(2-ethylhexyl) adipate.

For example, embodiment 38 is a continuous, free-standing film comprising the compositions of embodiments 1-37.

For example, embodiment 39 is a flexible package comprising the compositions of embodiments 1-37.

Embodiment 40 is the flexible package of embodiment 39 selected from the group consisting of a blister pack base, a strip pack base, a metal/plastic sheet, a paper/plastic laminate, a pouch, a wrap, and a bag.

For example, embodiment 41 is a rigid package comprising the compositions of embodiments 1-37.

Embodiment 42 is the rigid package of embodiment 41 selected from the group consisting of bottles, jars, ready meal trays, trays, cosmetic containers, squeezable tubes, and thin wall containers.

For example, embodiment 43 is an article comprising the composition of embodiments 1-37, wherein the article is made by injection molding.

For example, embodiment 44 is a continuous fiber comprising the composition of embodiments 1-37.

For example, embodiment 45 is a staple fiber comprising the composition of embodiments 1-37.

For example, embodiment 46 is a nonwoven fabric comprising at least one continuous fiber comprising the composition of embodiments 1-37.

Embodiment 47 is the nonwoven fabric of embodiment 46 comprising a plurality of continuous fibers comprising the composition of embodiments 1-37.

For example, embodiment 48 is a medical-related article selected from the group consisting of: an isolation gown, a surgical gown, a surgical drape, a surgical cover, a surgical mask, a surgical scrub suit, a surgical cap, a gloves, a shoe cover, a bath wipe, and a wound dressing; wherein the medical-related article comprises at least one fiber comprising the composition of embodiments 1-37.

For example, embodiment 49 is a filter selected from the group consisting of: a gasoline filter, an oil filter, an air filter, a water filter, a coffee filter, a tea bag, a liquid cartridge, a bag filter, a vacuum bag, an allergen membrane, and an allergen laminate; wherein the filter comprises at least one fiber comprising the composition of embodiments 1-37.

For example, embodiment 50 is a hygiene-related article selected from the group consisting of: a wipe and a backsheet a pad, a diaper or a cloth; wherein the hygiene-related article comprises at least one fiber comprising the composition of embodiments 1-37.

For example, embodiment 51 is a sanitary-related article selected from the group consisting of: a baby hygiene product, a child hygiene product, a female hygiene product, an incontinence product, a pads, an absorbing pad, and a wiping cloth; wherein the sanitary-related article comprises at least one fiber comprising the composition of embodiments 1-37.

For example, embodiment 52 is a hot melt adhesive comprising the composition of embodiments 1-37.

For example, embodiment 53 is a sealant comprising the composition of embodiments 1-37. 

What is claimed is:
 1. A composition comprising a polyalpha-1,3-glucan compound represented by the structure:

wherein: (i) n is at least 6 and (ii) each R¹ is independently selected from H or an acyl group, the acyl group being independently selected from the group consisting of: a) an acetyl; b) a benzoyl; c)

 wherein a is independently 7-24; and d)

 wherein R³ can be independently selected from H atoms, linear alkyl groups, branched alkyl groups, cyclic alkyl groups, and aryl groups comprising from one to 24 carbon atoms; and with the proviso that if R¹ is acetyl then at least one other R¹ is

 wherein a is independently 7-24 or a benzoyl; and wherein the poly alpha-1,3-glucan compound has a degree of substitution of from 0.001 to
 3. 2. The composition according to claim 1, wherein a is independently 9-16.
 3. A composition comprising: (A) a polyalpha-1,3-glucan compound represented by the structure:

wherein: (i) n is at least 6 and (ii) each R¹ is independently selected from H or an acyl group, the acyl group being independently selected from the group consisting of: (i) an acetyl, (ii) formyl (ii)

 wherein a is independently 0-6; wherein said composition has a degree of substitution of from 0.001 to 3; and (B) a plasticizer.
 4. The composition according to claim 3, wherein the plasticizer is selected from the group consisting of phthalate esters, phosphate esters, glycerol esters, triethylene glycol based esters, and esters of adipic acid, azelaic acid, citric acid, sebacic acid, and tartaric acid.
 5. A continuous, free-standing film comprising any of the compositions of claim 1 or
 3. 6. A flexible package comprising any of the compositions of claim 1 or
 3. 7. The flexible package according to claim 6, wherein the package is selected from the group consisting of: a blister pack base, a strip pack base, a metal/plastic sheet, a paper/plastic laminate, a pouch, a wrap, and a bag.
 8. A rigid package comprising the composition of claim 1 or
 3. 9. The rigid package according to claim 8, wherein the package is selected from the group consisting of: bottles, jars, ready meal trays, trays, cosmetic containers, squeezable tubes, and thin wall containers.
 10. An article comprising the composition of claim 1 or claim
 3. 11. The article of claim 10 prepared by melt processing.
 12. The article of claim 10 in the form of a continuous or staple fiber.
 13. The article of claim 10 in the form of a nonwoven or woven fabric.
 14. The article of claim 10 in the form of a filter, hot melt adhesive, or sealant.
 15. The flexible package of claim 6 having a total luminous transmittance (T_(t)) of at least 60 percent when measured according to ASTM D1003:13. 